Showing posts with label problem-solving. Show all posts
Showing posts with label problem-solving. Show all posts

Tuesday, April 21, 2015

Solving Difficult Problems

Don't Panic!

My students have been brought up in the math tradition of fast is best, and there's only one way to solve problems, using tried and "true" procedures. Their previous physics teacher had selected a college textbook for them (thinking they were all AP-Physics students, which they were not, even though they were all very intelligent in their own ways.) The textbook took great pride in generating formulas for every conceivable situation, so my students had great difficulty accepting my collection of 4 formulas on the board, which I said would cover any situation they could think of that applied to Newton's 3 Laws. Time and again one of the students (usually the ones who had gotten high grades from the previous teacher) would bring that textbook to me and ask if some version of a formula was the right one to use for a particular problem. I always said, "No, use one of the four on the board." This was very difficult for them to accept until I discovered a wonderful video clip, which I show below.
I have been auditing a MOOC with Stanford Professor Keith Devlin, based on his book Introduction to Mathematical Thinking. ("Auditing" means, I'm not taking it in the allotted time, nor submitting assignments, but I'm at least watching all the video lectures.) In the very first week, he offered a video, which I called How to Solve Difficult Problems.

Techniques the Pros Use to Solve Hard Math Problems from Keith Devlin on Vimeo.

I think showing a clip from this (about half) was the turning point in getting students to understand what I was talking about.The course is intended to introduce HS students to what college math (beyond calculus) will be like, and I am auditing it, so I can mentor my students in what they need to know to succeed in college. One important thing is problem solving - not just math and physics, but everyday life away from home. So we talked about his recommendations
  • Don't panic
  • take your time
  • take a break
  • draw a picture or diagram
  • write down everything you know
  • learn from your mistakes, etc
in connection with problem solving in everyday life - deciding which college to apply for or accept, whether to buy a car, and which one, whether to date someone, etc. 
And then we applied these concepts when solving physics problems. After the video they had a much better understanding of how to solve problems. Interestingly enough, on the last test I gave them, they were very good at solving problems where they were expected to model the problem in 6 different ways, but they did poorly on multiple-choice, where I figure many rushed through in their usual manner, bringing in all their physics misconceptions.

Friday, May 24, 2013

Sometimes I wish I was teaching with chalk on a blackboard


I have been using computers since about 1965, when I learned to program in Fortran for a possible dissertation topic. (I ended up not using it, though) and then about 15 years later teaching students at a high school in Denmark about computers and how to use our very primitive school computers.

In the years since then, I have learned html, css and java script to make websites, like my own site at byelverton.net and even xml and Visual Basic, which was becoming popular for technical writers (my in-between career.) On my computer I have most of Adobe's products, Microsoft products like Visio, interesting fonts, MathType, SnagIt, Prezi, and numerous educational programs like Sketchpad, Fathom, something called Green Globs, etc. to use in teaching math and science.

But computers don't always work. 

And gone are the days when I can call in a computer-savvy friend to fix what went wrong. I picked my current Dell desktop {which has just crashed 2 times since I wrote those words] because it had lots of USB ports, since almost everything, mouse, keyboard, external drives, scanner, headset, and even webcam and screens, have to plug into the computer through these ports - which is a great improvement, except that now there aren't enough ports for everything we used to use dedicated ports for.

And the big problem is, when it crashes, NO ONE has a clue what's causing it anymore. I know that because I finally got tired of having keyboard and mouse freeze (and scanner and the one screen plugged into the USB port, and the headset while I'm on Skype or Rosetta Stone) one or 2 at a time. Since I currently don't have a job, I don't even have access to my school's tech team, so I'm alone on this one.

It took me a long time to figure out that the problem was the USB ports, after paying the tech from Staples (less than a year after I bought it) $99 to run a test on it after the freezing began to happen with increasing frequency - as just now with about 2 minutes after restarting the computer.

And customer service doesn't work either

But some companies have gotten too big to serve their customers - Staples says the warranty (which has now passed) is with Dell, not them. I have been on the phone or chatted with tech support from Dell in India countless times (actually I have kept a log of the errors and a record of most of the contact with India.) Each person has taken over my computer, fixed something and let me go. After which Windows has decided that it needs to repair what they did and gone back to an earlier time. Twice a local tech has come to install parts - and it froze immediately afterwards.

What I want is a new replacement computer. What they want is to replace the hard-drive, or reinstall the OS, in either case losing all the installed programs, which I would have to spend hours locating and installing. With a new computer, I'd at least be able to transfer the major programs over a cable. Also, there is no way they're just going to take my hard-drive with all my personal information on it before I've wiped it clean. (I worked as a technical writer for a company that produced software to find hidden deleted files on computers, like porn and espionage, so I know that it has to be reformatted before I let it go!)

I have spent hours communicating with them, and waiting for my computer to wake up again; Dell's techs have spent hours communicating with me, and replacing minor parts in my computer. If they had replaced it as I requested at first, we would all have been saved enormous amount of time - which in my book is money. This is bad business practice for Dell, and I certainly will never buy their products again!

I have started a complaint with Better Business Bureau in Austin, but so far Dell holds tight, and is trying to keep correspondence away from BBB.

But my advice is, don't buy Dell. I'm not quite sure who one can trust with decent customer service. Some of my relatives say Apple. But I'm not ready to go there yet. We'll see.

Wednesday, September 23, 2009

Making Math Problematical


Since I don't have a job yet, I've been doing a lot of extra reading about math pedagogy, wishing I had a class to practice things on. The most exciting I've found so far is Teaching Mathematics through Problem Solving, which unfortunately is out of print (but available used from Amazon). There is a version for PreK-6 and one for 6-12. My first attempt to buy it brought me the PreK-6 book, which I read until the 6-12 arrived today, so I have a head-start on the concepts I'll be reading about. But I thought I'd write a little about my ideas about problematizing math before I get into the book.
My father studied mechanical engineering in the 1930's at Stevens Institute of Technology in Hoboken, NJ, which he always felt was an excellent education. He used to tell me that they had not tried to teach him a lot of facts and formulas (which of course would often be out of date before he had a chance to use them) but how to find the facts and derive the formulas. My college physics professor 30 years later also impressed upon us that we shouldn't learn a bunch of formulas, but instead understand the concepts so we could set up the problems without formulas. With a formula you just have to plug in a few numbers and get answers, but if you don't understand what you're doing you have no way to know if the result it reasonable, or if you, for example, used the wrong units.

From the experience of watching my children grow up, I know that they were more willing to accept facts, rules, whatever, if they had discovered them themselves. In fact, I wrote in my "Mission Statement" for a class this summer:

Through experience with my own children, I know that the younger generation does not want to be fed with my knowledge and experience. Young people learn only what they think they need to learn. Furthermore, they want to experience life themselves, not vicariously through their elders. Any other “learning” remains in short-term memory and can rarely be utilized in their explorations of life. I believe that I can best help young people select what to learn by exposing them to own my passion for learning and exploring; I want to encourage them to maintain their childhood curiosity, rather than to suppress it.
I recall that my son usually wanted to do things his own way, even if that way was much more difficult, including climbing up a steep incline instead of taking the stairs. (Of course there were other times when he was feeling lazy that he wanted me to do things for him...)

We get stronger when we do things, we get better at things when we do them often, particularly if we think about how we are doing them. That's how we learn skills. Kids know all about understanding. That's what they spent the first 5 years of their lives doing, mostly without our help, because they had to figure it out on their own. We don't want them to stop trying to understand when they get to school. Skills aren't enough, and can be forgotten. Understanding can be recalled when needed.

Education has had a variety of methods through the years. Socrates had figured out that people needed to figure things out themselves, way back then! But somewhere along the line there's always some know-it-all who figures s/he knows the best way how to do something and wants to save others the difficulty of having to figure it out themselves, or maybe the tragedy of never figuring it out. We all have been know-it-alls at some point or other. (Like when talking with someone who has an opposing view on some topic dear to our heart. Of course they're wrong and we need to make them understand why!) I remember my (then-)husband trying to teach my son how to crawl(!) Why couldn't he figure out how to move one arm forward, not backwards?

I read a really telling example in another book recently about famous environmentalists. One of them as a child had found a couple of caterpillars and followed their life-cycle. After watching the first pupa open to reveal a butterfly struggling to get out, he decided to help the other butterfly, so it didn't have to struggle. But that one never learned how to fly. It was too weak, because it didn't have to struggle.

So by problematizing math, we make students struggle (a little) to figure things out rather than telling them how to do things. We give them a new problem based on knowledge they have already figured out and understood, and let them figure out how to solve it. If different students come up with different methods (resulting in both correct and incorrect answers) we let the students reflect on the methods so that they can decide which ones are most elegant (I love that mathematical term!) are easiest to understand and can be varied to solve other problems, as well as how not to fall into pitfalls that produce the incorrect answer. Then the students can own the methods they understand rather than the steps and skills we present to them. They learn how to understand, rather than formulas to plug numbers into.

Unfortunately there are many who think we should be taking the problem out of math, to make it easier some how. (In my practice teaching this summer we never presented a single word problem, much less have the students figure things out themselves. It ended up being a lot more difficult getting them to remember stuff than if we'd taken the time to help them understand.) There are others who think we should make math "fun." But isn't it more fun to figure things out yourself? Isn't it more inspiring. Don't you remember those things better, and can't you use them in other situations?


I just noticed that one of the editors of this book is an author in a new series Core-Plus Mathematics for which I just bought the (relatively inexpensive) teachers' guide,

  • ... a standards-based, four-year integrated series covering the same mathematics concepts students learn in the Algebra 1-Geometry-Algebra 2-Precalculus sequence.
  • Concepts from algebra, geometry, probability, and statistics are integrated, and the mathematics is developed using context-centered investigations.
  • Developed by the CORE-Plus Math Project at Western Michigan University with funding from the National Science Foundation (NSF), Core-Plus Mathematics is written for all students to be successful in mathematics.
My mind is already working out ways to used problematical math in the classroom. I hope I have a classroom where I can use my ideas soon!